Basal Metabolic Rate and Total Energy Requirement Calculator
The basal metabolic rate (BMR) represents the energy requirement of an organism at rest, i.e. the number of calories needed to carry out vital metabolic functions (breathing, blood circulation, etc.). It is measured in kilocalories (kcal) under the following conditions: 1) the subject must be awake and at rest; 2) fasting for at least 12 hours; 3) having had a restful night; 4) not having performed intense physical activity in the hour before measurement; 5) no physical or mental excitement; 6) ambient temperature between 20°C and 27°C. The calculator estimates the average BMR by entering sex, height, weight, and age. To calculate the total energy requirement, you can also select the activity level and any pathological stress factors.
Note: you may use either a dot (.) or a comma (,) as decimal separator.
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Basal Metabolic Rate and Daily Calorie Requirement
Men — Harris-Benedict revised (Roza & Shizgal, 1984):
BMR = 88.362 + (13.397 × kg) + (4.799 × cm) − (5.677 × age)
Women — Harris-Benedict revised (Roza & Shizgal, 1984):
BMR = 447.593 + (9.247 × kg) + (3.098 × cm) − (4.330 × age)
Children — Harris & Benedict (1919):
BMR = 22.10 + (31.05 × kg) + (1.16 × cm)
The total calorie requirement is obtained by multiplying the BMR by the activity coefficient (1.2–1.7), to which any pathological stress factor is added.
Sources: Harris J, Benedict F. A biometric study of basal metabolism in man. Washington D.C., Carnegie Institute of Washington, 1919. — Roza AM, Shizgal HM. The Harris Benedict equation reevaluated. Am J Clin Nutr, 1984;40(1):168–82.